Fridge not cold enough

[dtrue]

Hi BC, Did read most all post re today, with no knowledge of boats origin. BeAdv. the Danfoss units are good and were developed for mobile application BD" units 12-48v and refrigerant used was R600 (k) and 290 (cn)theses are both flammable refrigerants used from design in certified vessels with little to no oily residue at leaks point. Danfoss use 134a as well (which will leave oily residue as well... check for a tag. models with K(BD35K...and are likely to be using R600a Back to work matey... dtrue

[icemate]

Definitely sounds like you are low on refrigerant. No big deal anymore as you can buy Leak Seal at your local refrigeration wholesale house. Evacuate the system, use vacuum pump and connect leak seal tube to unit, put refrigerant on scale and weigh in the manufacturers recommended charge. This will work fine and you will not have to replace unit and leak seal will stay to help any other potential weak spots you may have. Enjoy sailing and live.

[skipgundlach]

can you post a pic of the compressor? The typical hi and lo pressure fitting is either a schrader valve or the quick-connect as you would have in an auto AC...

And check with your manufacturer about anything other than pure refrigerant; when I had a Frigoboat, they used a capillary tube as their expansion device. It's VERY prone to fouling.

And any competent refrigeration guy should be able to insert a filter-drier. The basic issue with any (note that I'm not a refrigeration guru) Danfoss compressor I've seen is that the filter-drier is right next to the hot compressor and as a result, stuff is still in aerosol condition (hot) so water doesn't dry out.

If yours is different (not an issue of clogging potential with anything in the refrigerant), you could try it. But trying some added refrigerant to see the results is a pretty easy test.

[Richard Kollmann]

I read most posts regarding boat refrigeration troubles and am amazed at how scarce the actual facts of what is wrong get distorted by foolish guessing. Advice to buy a new refrigeration system without confirmation by non destructive tests is a mistake. I have seen two systems in the last year replaced to find the new units developed the same trouble as the old one.

What facts do you have that there is refrigerant blockage? Refrigerant flow plugged is extremely rare on air cooled BD compressor systems. This compressor no longer cycles off now that thermostat and speed control are removed. Problem remains that frost is missing from evaporator what is amperage draw of compressor? Is there cold wet condensation on evaporator’s surface indicating moisture in capillary tube? Indicating freezing and thawing at around 33 degrees F. Is amp draw after compressor running for 20 minutes 3 .5 amps or below?

To test for refrigerant volume and flow when speed and thermostat controls are bypassed add 134a refrigerant till ammeter is stable at 5 amps and no higher. If connected the trouble LED will most likely not flash. Running at 5 amps if LED gives a 3,4, or5 flash code Run a new test ground wire from module ground terminal direct to battery ground post.

If you are able to have a low pressure gauge connected to suction side of refrigeration unit monitoring gauge during this test will confirm moisture or solid material blockages as well as correct volume of refrigerant when cross referenced to amperage.

Never follow advice to open up a system until problem is isolated. If it is confirmed there is a loss of refrigerant find and repair leak then replace filter mechanically with specally designed refrigeration flare nuts. Do not solder new filter in.

[thunderhoof]

I had exactly the same problem with my Frigoboat AV35F installation, about 12 years old. I had recharged the system a few time before that stopped having any effect. When I got serious about fixing or replacing it I looked at the cost of a new compressor and decided fixing was the call.
After a little study I found that contamination of the system with air and water is the most likely culprit. Also, the rubber gaskets at the quick disconnect fittings get tired and need replacing.
I bought a vacuum pump, an automotive a/c service kit with manifold and gauges and some fittings to mate with the connectors at the compressor.
For my case I evacuated the compressor for several hours and then waited to see if the vacuum held. Good news - it did. Then I refilled the system after purging the external lines of air. The correct fill for my system is to place the R-134A can upright and refill only with gas. I repeated the evacuate - refill sequence and the fridge now works fine.
After the initial cool down the fan runs about 20 of each 50 seconds, much less after a day of operation.
Of course I could have a HVAC professional do this, but I figured that with $160 invested in tools I more than broke even.
My message is that you consider trying to purge and recharge the system before you spend $$$$ on new hardware.

[bcboomer]

Thanks for jumping in Richard.

The compressor is drawing 1.7 amps.

The evaporator may have been damp when the compressor was allowed to cycle but, now that it is running constantly, it is dry and 45F on my cheap IR thermometer. The frosted area is gradually extending a few inches.

I'll rig an additional ground and see if anything changes.

Is there a standard tee fitting that will fit into the Vitrifrigo connector?
I'm only familiar with systems that have accessible fittings.

[bcboomer]

Thunderhoof

I don't think there are any O'rings in this system.
If I can figure an easy way to get into the system I may follow your path but I'll do a little more testing 1st.

[bcboomer]

So, back to my fridge. (49th anniversary interfered with boat repairs yesterday)

After running constantly the compressor is now drawing 2.7 amps.
Running a new ground straight to the batteries made no difference.

Still lots of questions:

If I go the evac, recharge route do I do each half of the system independently and rely on the existing valves to seal the charge in each section?

Is there any way to determine if there is a blockage or should I back-flush some R134a and install a new receiver/drier?

I assume I should cut out the old receiver/drier.

Is there any issue with releasing a little R134a into the atmosphere or is it considered benign enough?

Thanks in advance for the advice. I understand that even those giving advice with only their limited personal experience mean well but it is the advice of the professionals like Richard Kollmann that are the most important.

[Typhoon]

Hi Neil
What do you mean by "each half of the system ? You leave the system intact and evac though the access port on the compressor .

Also have you determined that there is any refrigerant even left in the system ? If there is you should recover it .

Do you have all the tools and equipment to undertake this task and of course expertise ?

I am cautious to ever advise someone to open up a system . I do this everyday but it is a bit of a learning curve . You don't want to have the same problem to reoccur.

Regards John

[bcboomer]

Hi John,

I was thinking that if the system was divided at the existing connections, which have valves, then each part, the compressor-condenser portion and the evaporator side could be flushed separately. I'm embarrassed to admit I never got my head low enough to see the little access port on the top side of the compressor. Certainly simplifies things.
I haven't taken a cfc handling course since the phase out of R12 and at that time, in BC, one couldn't let any R12 or R134a escape. I wonder what happened to all the R12 we turned in. Hopefully not just resold in another jurisdiction. Certainly there is still R134a in the system as the veggies and bubbly are still cold.
From the discussions I've read on this forum and others it seems R134a is readily available and casually handled. I thought perhaps new information had resulted in relaxing the release of R134a.
I don't have the equipment to evacuate and store the R134a in the system so perhaps I'm stuck getting a professional to do that.
If it is reasonable to do, I'd still put in a drier myself and, depending on prices, evacuate, test and charge the system myself.

[thunderhoof]

Organizations that evacuate refrigeration / air conditioning units are required to capture, recycle or dispose of R134a. I think most requirements follow from the use of R12 and the other Chlorine based refrigerants. I cannot find any reference to an enforceable requirement for handling the few ounces small refrigerators contain. The only relevant citation I found uses the words "capture whenever possible".
I cannot imagine how multiple refrigeration system would be linked except at the control level (maybe) so I suggest you treat each one separately.

[Typhoon]

Hi Neil

The couplers may not be resealable , they may be one time use . So if you open them you will lose any refrigerant in the system . Strange that you would have access valves at that point . Take a picture of them . This tells me that someone has worked on the system before your ownership . Again these may not be resealable couplers if they are not I would just use this access valves as high and low pressure sides and evac accordingly. Now another problem you are going to run into is that you cannot buy R134a in Canada over the counter. In many places you travel it is controlled substance and you will need your CFC handling ticket to buy it . Not sure if you buy it in small amounts . I think the US is the only place you can buy it in small cans at the auto parts stores. You can get R12a which is a hydro carbon refrigerant you will have to make your own decision whether or not you want to put that inside your boat . There's lots of information to be found about it , google time . Also you can't buy the solder or the flux up here without a Hvac license either . These things are all special for refrigeration you can't use plumbing solder . Unless you braze the system and that has its on challenges first you should fill the system with a nitrogen purge to stop scaling residue from the hi heat entering the system that is needed for brazing . Then you really must be concerned about not setting you boat of fire , also brazing anneals the copper and makes it prone to breaking when you bend it . If you have a vacuum pump you should really have a micron gauge as well and know how to use , also a schrader valve remover tool with a side port so you can pull your vacuum without the valve in place all expensive pieces of equipment for a one time use . There are many things to understand before you attempt to repair your existing system. Proceed cautiously.

Regards John

[bcboomer]

Thanks John,

That's what I was wondering. Things haven't changed for accessing R134a and it seems no-one has come up with a better alternative. I wonder how Amazon Canada gets away with selling 134a.
The valves I referred to are the poppet valve described in the installation manual but there is no reference to re-opening the system and using them again. They are contained within the connector fittings to hold the original charge.

As far as putting in a flammable gas goes, that isn't happening. That stuff was a pain to deal with in automotive systems. It contaminated our recovery canisters and should be banned too. Everyone who uses one of these DIY kits is breaking the law.

I guess I'll have to bite the bullet and get someone to come in and fix it, or at least evacuate it so I can pull it out. I've had poor service from local "professionals" and seen even worse on neighbour's boats so my first response to a problem is to fix it myself, even if it means spending a bunch on tools.

[Richard Kollmann]

Bcboomer, It sounds like you have come to the conclusion that your unit is confirmed to be low on refrigerant. The next step is to add the correct 134a refrigerant to unit bringing amperage from 1.5 to 5 amps stabilized and no higher. This will require 3 to 5 ounces of refrigerant and a servicing hose with correct connections to refrigerant can and fitting on compressor.

Next step is to find and repair refrigerant leak. If you need help finding leak email me for details on leak detection on that unit without expensive equipment.

As to whether vacuuming dehydration or a new filter/dryer process is required that decision can be addressed after normal operation period of a week or more.

It was the intention of the Montreal Clean Air Act agreed by 24 countries to reduce air emissions of some refrigerants. Countries individually developed regulation regarding refrigerant handling. The actual compliance of these regulations are left up to local and federal offices. Special interests in the HVAC and R industries would prefer for financial reasons want all work of this nature to belong to them. If local regulatory people permit 134a refrigerant and some of the new blended replacement refrigerant to be sold and used by individuals in there equipment it must be legal. It should also be understood that it is except able to continue to use Freon R12 in any system designed for it in the US.

[bcboomer]

Thanks Richard,

If I recall correctly, in BC it is illegal to vent R12 or R134a to the atmosphere and it is illegal to add R12 to any system. The rational being that, if it is leaking, it must be repaired and converted to R134a. That may help the industry but the end result is less crap in the atmosphere. When I was in business we were forced to buy a recovery/recycling system or give up that end of the business.
I'll send a PM as I would like to be able to find the leak without a sniffer. As I recall the sniffer we had really didn't work as well as the R12 ones did. Smaller molecule was the excuse we got. If I can find a leak and repair it, should be simple to get it topped up.